As marijuana legalization continues to spread and mercifully drag the normalization of cannabis use with it, law enforcement across the nation is scrambling for a reliable way to detect THC-induced driver impairment. The legalization of marijuana across many U.S states including Michigan has led to lansing dispensary centres becoming more and more popular, though this has also increased the number of people driving under the influence of cannabis.

Plenty of blood and urine tests exist to detect marijuana in a person’s system, but they fail to meet two major needs of a handheld roadside tool: determining whether a subject is impaired at the moment (the metabolites they detect can linger in fat cells for weeks) and providing instant results. What law enforcement needs is the marijuana equivalent of an alcohol breathalyzer, and the company that develops the technology first stands to make a killing.

One company appears to be a frontrunner: Hound Labs, conveniently located in freshly rec-approving California, has seen its The Hound portable marijuana detector tested by Oakland officers for the past two months, thanks to its founder’s unique situation.

Mike Lynn, an emergency room doctor in Oakland, is also a reserve officer with the Alameda County Sheriff’s Office — he helped pull over drivers and administer the initial field tests last September. The CEO of Hound Labs developed his device with the help of chemists at University of California-Berkeley.

The tests, which were administered on a volunteer basis in an attempt to collect data to validate the THC-detecting technology, were a success in Lynn’s opinion:

Two people admitted smoking marijuana within the past 30 minutes, Lynn says, and in a satisfying validation for his technology — created with University of California chemistry assistance — their readouts were much higher than the rest.

Other drivers, he says, admitted to smoking marijuana within the two-to-three-hour window that the device appears able to detect the high-inducing compound THC (tetrahydrocannabinol) on a smoker’s breath, and the test confirmed it.

Hound plans to sell the device at a price point under $1,000 when it becomes available next year, and make inexpensive single-use cartridges for the device. The Hound will also test for alcohol, so officers won’t have to carry multiple impairment-detecting gadgets. Lynn says he’s received interest not just from law enforcement, but from employers who want to test employees without having to wait for lab results.

Meanwhile, defining stoned driving remains a problem. As Scientific American points out, even experts remain highly uncertain about marijuana’s precise effects on cognition and competence, and an individual’s tolerance can wildly skew the impact of said effects. Until the science is perfected, society will likely face a long future with two imprecise detection methods: (1) a test like Hound’s which provides an exact-but-imperfect number, and (2) the subjectiveness of law enforcement. For now, it’s just the latter.

“I think for most of our officers, impaired is impaired. They can see that based on their training and experience,” Sgt. Davis Dowty with the California Highway Patrol told KTXL this week. But, he says, that’s not always enough to get a conviction: “Because they don’t have a tool, like with alcohol, it’s very [easy] for them to say, ‘Okay. All these things that you saw, that’s wonderful and you may have been right, officer. But we need to convince a jury.'”

Watch The Hound in action here: